Preheat the barbecue for medium high heat and oil grate. Lightly pound chicken to flatten. Trim excess fat from edges. Brush with olive oil then season both sides of chicken with salt, pepper, garlic powder, onion powder, oregano and chilli flakes.
In a medium bowl combine the sun-dried tomatoes, olives and about 2 1/2 tablespoons oil from the tomatoes. Season with salt and pepper to taste; set aside.
Place chicken on preheated barbecue and cook for 10 to 12 minutes, turning in different directions while cooking to get cross-hatch grate marks. Place cooked chicken on rolls and top each with a heaping tablespoon of tomato mixture.